Switch



Nov. 22, 1960 P. M. HIGGS 2,961,507

SWITCH Filed Feb. 28, 1950 3 Sheets-Sheet 1 INVENTOR.

PAUL M. mess FIG. 2

IQTTORNEY Nov. 22, 1960 P. M. HIGGS SWITCH Filed Feb.' 28, 1950 5 Sheets-Sheet 2 46 43 I: I f! I 42 37 28 39%| F I G. 4

21 26 390 v 2 I 64 '1 r H l I L f9 I6 INVENTOR.

I PAUL M. mess ATTORNEY Nov. 22, 1960 P. M. HIGGS 2,961,507

SWITCH Filed Feb. 28, 1950 3 SheetsSheet 5 INVENTOR.

PAUL M. HIGGS BY (V0 ATTORNEY SWITCH Paul M. Higgs, Seattle, Wash., assignor to the United States of America as represented by the Secretary of the Navy Filed Feb. 28, 1950, Ser. No. 146,802

4 Claims. (Cl. 20083) The present invention relates to an improved pressureoperated deactivating switch which, while suitable for various purposes, is especially designed for use in a submarine torpedo as a controlling element for the electrically operated detonating mechanism, to prevent premature, or other undesired, explosion of the torpedo.

Service tests show that when a torpedo, which has been set to run at a shallow depth, broaches, or emerges from the water, and encounters heavy seas, its warhead may be battered by waves, with the result that mechanical stresses may be transmitted to the electrically operated detonating mechanism and premature detonation of the torpedo eifected. Moreover, the warhead of a running torpedo can be influenced by the effects of an underwater explosion in such manner as to result in a premamature explosion of said torpedo. Such underwater pressure and effect, or countermining, may result from detonation of an enemy-set explosive charge, or from the explosion of one torpedo among a group of running torpedoes.

- Under these noted conditions, and under other similar circumstances, the novel control mechanism of the present invention becomes operative to deactivate the electrical detonating mechanism and prevent firing of the torpedo.

More particularly, one of the principal objects of the invention is to provide a unitary electrical device embodied in a torpedo and including, in combination, one set of contacts forming a ceiling switch, to operate on broaching, and a second set of contacts forming an anticountermine switch, both operable upon changes in hydrostatic pressure, for controlling the electrical detonating mechanism of the torpedo.

A further object of the invention is to provide a means for deactivating the detonating mechanism prior to the time that the torpedo is used.

Another object of the invention resides in the provision of a unitary electrical device which includes a minimum number of parts that may readily be manufactured and compactly assembled to produce a sensitive control mechanism that may with facility be installed in a torpedo.

Other objects and many of the attendant advantages of this invention will be appreciated readily as the same becomes understood by reference to the following detailed description, when considered in connection with the accompanying drawings, wherein:

Fig. 1 is an assembly view, on a reduced scale, of the switch unit and its connecting cable and plug;

Fig. 2 is a detail axial sectional view, considerably enlarged, of the switch structure;

I Fig. 3 is a transverse sectional view on the plane 33 of Fig. 2, showing details of the switch structure;

Fig. 4 is a detail elevation at right angles to Fig. 2, with the housing and liner partly broken away and in section;

7 Fig. 5 is -a semi-diagrammatic view, in section through fastening the unit in a recess in the exterior wall of the the contact mechanism shown in Fig. pair of the contacts closed;

Fig. 6 illustrates the same mechanism and circuit, but with the, said pair of contacts open; and

Pig. 7 illustrates the same mechanism and circuit, with the mechanism in a of contacts provided.

Referring to Figs. 1 and 2, the switch unit is enclosed in a cylindrical cup or housing 10 having an attaching flange 11 with'holes 12 to accommodate screws for 2, showing one torpedo with its outer face, best illustrated in Fig. 1, flush with the outer surface thereof. A cable 13 terminating in a plug 14 is employed to connect the switch into the electrical circuit which detonates the explosive charge of the torpedo.

As seen in Fig. 2, the wall of the housing or cup 10 is thickened near its outer end to form an annular shoulder at 15 to receive a transversely disposed partition 16 having an axially located bore 17; and an insulating liner 18, of cylindrical shape and having an elevated bottom 19 provided with an axially located opening 20, is clamped against the inner face of this partition by means described hereinafter. A portion of the cylindrical wall of the liner 18 is cut away as shown at 18a, Fig. 3, to permit inspection of the assembly during manufacture.

The operating parts of the switch are mounted upon a flexibly suported, or floating, metallic inertia bar 21, of relatively large mass and having an enlarged end, arranged diametrically in the housing and supported by a flat, arcnate steel spring 22. the spring is welded or clamped in an end kerf in the enlarged end ofthe bar 21 and the opposite ends of the spring are fixed by screws 23' upon, two mounting posts;

24, secured to the liner bottomI1-9by'screws 25'. An: adjustablecontact, formed by the lower 'end of'a' screw 26, is mounted in the free end of the bar 21 and insulated therefrom by a bushing 27 of Bakelite or the like. A terminal 28 for a flexible electrical conductor such as a wire is mounted on the contact screw.

A resilient metallic tongue 29, of relatively small mass, is secured by one end to the under surface of the thickened portion of the bar 21, and extends beneath said bar and parallel thereto. This tongue is stiffer than the arcuate spring 22. A contact 30 is mounted on the up per surface of said tongue near its free end and is designed to cooperate with the contact on the screw 26, while an insulated button 31 is mounted on the under surface of said tongue opposite the opening 20 in the bottom 19 of the insulating liner 18. At its free end and on its under surface, the tongue carries a contact stud 32, which co-acts with a contact 33 on a resilient metal contact bar 34 one end of which is rigidly mounted upon the insulating bottom 19 of the liner 18. The free end of this contact bar 34 is provided with a stop screw 35 (Fig. 4), adjustable with relation to the bottom 19 to vary the position of the contact 33, and fitted with a lock nut 36. An arched bridge block 37 of insulating material is fastened to the bottom of the liner and spans the bar 21, to form a stop to limit movement of said bar, and to form a support for spaced terminal lugs 38 and 39. Conductors 4t) and 41 of the cable 13 are connected to these lugs.

The chamber containing the operating parts of the switch is closed, and the liner 18 clamped in place, by a disk or cover 42 held in place by an annular nut or screw 43 externally threaded to engage a threaded portion of the open end of the housing 10 and bearing on the cover through a metallic plate 44 and packing 45. A central boss 46 on the plate 44 is bored and externally threaded to provide a waterproof entry-for the cable 13 by means position for closing the other pair The central portion of of packing 47, a gland 48 and a stufling nut 49. Additional waterproofing is provided by a washer 50 in said nut.

A bellows 51 of the Sylphon type is enclosed within a chamber 52 defined by the reduced outer bore of the housing for activating the switch mechanism, and one end of the bellows is attached to the outer face of the partition 16. The bellows is compressible under hydrostatic pressure applied against a flat circular head 53 which closes its outer end and rigidly supports a centrally located pin 54. The pin 54 projects through the orifices 17 and 20 in the partition 16 and linear bottom 29 to-.

ward the button 31 on the tongue 29 A coiling spring 55 for extending the compressed bellows is interposed be-v tween the partition 16 and the head 53. If desired, the spring 55 may be eliminated, provided the bellows alone can carry the load.

A diaphragm 56, of rubber or other elastic material, is mounted adjacent to the head 53 in the recessed or countersunk end of the housing, and the edges of the diaphragm are clamped in place by means of a flanged cover plate 57 and screws 58. The plate 57 is perforated to form ports 59 to admit water against the outer side of the diaphragm.

A suitable inert liquid of proper viscosity is preferably contained in the chamber 52 externally of the bellows 51, and providesa medium for transmitting pressure changes, reflected by movement of the diaphragm to the outer surface of the bellows assembly.

A threaded opening 60 centrally located in the cover plate 57 accommodates a set screw 61 which may be screwed inwardly to deflect the diaphragm by bearing against a metal disk 62 thereon. Such deflection of the diaphragm applies pressure, through the liquid contained in the chamber 52, to compress the bellows 51 and force the pin 54 inwardly to press against the button 31 on the tongue 29. Continued movement forces the bar 21 against the bridge block 37 and flexes the tongue 29 to close the contacts 26-30.

Referring now to Figs. 2, 3, 4 and'S, the conductors 40 and 41 of the cable 13 are connected to the terminal lugs 38 and 39, respectively. The lug 38. is connected to the inertia bar 21 and the tongue 29 through a conductor 38 1 (Fig. 3), one of the screws 23 and the arcuate spring 22; while the lug 39 is connected through a flexible lead 39a to the terminal 28:on the insulated screw contact 26 in the bar 21, and also through a resistor 64 and the con tact bar 34 to the contact 33 thereon. The conductors 40 and. 41 are connected through the plug 14 and a coacting receptacle, neither of which is shown in Fig. 5, to the terminals of a capacitor 63 forming a part of'the firing circuit of the torpedo.

Thus, it will be evident that the present device formsa switch in parallel with the firing capacitor63 and including two sets of contacts, either of which can short-circuit the firing capacitor. Closure of either set ofcontacts results in a quick discharge of the capacitor, thereby preventing its usual discharge through the squib of the electrical unit when the thyratron of the detonator unit becomes ionized and thus completes the circuit. The resistor 64 may be provided in series with contacts 3233 and be of sufficiently high resistance to prevent appreciable discharge of the capacitor upon only momentary contact. The set screw 61 in the threaded opening 60 serves as a safety means for preventing energization of the firing capacitor prior to use by closing the contacts 26-30 as hereinabove mentioned.

After launching, and during the torpedo run, water enters through the Prts59, thus subjecting the diaphragm to water pressure, theamcunt of pressure depending upon the running depth of the torpedo. This hydrostatic pressure, transmitted through the fluid in the chamber 52, compresses the bellows 51, and the pin 54 pushes against the button 31 on the tongue 29 to move it and the inertia. bar 21 inwardly against the 1 resilient resistancejof the spring 22. Under normal conditions, that is, when the torpedo is running at normal depth, this motion is suflicient to place the bar and tongue in the position shown schematically in Fig. 6, opening contacts 32-33, thus unshorting the firing capacitor 63 in the operating circuit so that it is allowed to charge and electrically arm the torpedo.

In this arming operation, and due to the rocking motion of the spring 22, which absorbs the movement transmitted through the tongue 29 to the bar 21, the contacts 26-30 remain open.

However, under excessive pressure on the diaphragm, as when the torpedo exceeds a predetermined depth, say 75 feet below the surface, the pin 54 jams the inertia bar 21 against the bridge block 37 and flexes the tongue 29 to close the contacts 2630, short-circuiting and discharging the capacitor 63.

The position of the contact 33 is adjusted by means of the screw 35 and lock nut 36 so that a minimum depth of, say five feet must be reached by the torpedo before the pressure will open the contacts 3233.

Thus, if the torpedo runs at a depth of less than five feet, or broaches, the contacts 3233 are closed to prevent firing due to the shock of waves; at depths between five and seventy-five feet contacts 3233 are open, and contacts 26-30 remain open so that the torpedo may be electrically armed; and at depths greater than seventyfive feet contacts 2630 are closed to deactivate the electrical unit, and thereby prevent end-of run firing of the torpedo.

As an anti-countermine device, and as a protection for a group of torpedoes against premature firing of one of its number, the sudden pressure from an underwater explosion compresses the bellows 51 and the push pin 54 flexes the tongue 29. Since the bar 21 has a greater mass and weight than the tongue 29, the cont-act 26 remains almost stationary for an instant, while the tongue s being flexed, and therefore contact 39 is pushed against ntact 26, thus scrt-c'rcuiting the capacitor 63, and -reventing premature explosion of the torpedo; This action is possible because of a small electrical delay in the expoder circuit which permits the contacts to close before the signal can pass through the circuit to the firing thyratron.

Obviously many modifications and variations of the present invention are possible in the light of the above trical contacts movable with said arm, said contacts being on opposite faces of the arm, a relatively stationary contact coacting with one of said movable contacts and normally in engagement therewith, an inertia member, a.

contact carried by said member in a position to coact with the other of said movable contacts but normally out of engagement therewith, said arm being movable by said. actuating means in response to hydrostatic pressure for.

disengaging the first mentioned movable contact from the relative stationary contact and engaging the second mentioned movable contact with the contact on the inertia member, and resilient means supporting said inertia memher.

2. An electrical switch for torpedoes, comprising a bellows movable in response to hydrostatic pressure, a spring opposing such movement, a flexible arm, a pair of electrical contacts on opposite faces of said arm, a pair of relatively stationary contacts carried by the switch to cooperate with said movable contacts, means operated by the bellows and,coacting with.saidflexible arm-,gto

deflect the said arm and thus control the contacts, and an inertia member carrying one of the relatively stationary contacts, said inertia member varying the manner of response of the switch to sudden shock and to steady state operation.

3. An electrical switch for torpedoes, comprising an element movable in response to hydrostatic pressure, a spring opposing such movement, an actuating means coacting with said movable element and moved thereby, an inertia member, a contact carried by said member near one end thereof, and insulated therefrom, resilient means supporting the other end of said member, a resilient strip secured at one end to said last named end of the member, and a contact carried by said strip to coact with the contact carried by the inertia member, the actuating means being located to engage said strip near the mid-point of the latter, whereby a sudden increase at hydrostatic pressure will cause the two contacts to engage, whereas a gradually applied hydrostatic pressure will fail to close said contacts.

4. In the switch according to claim 3, additionally a relatively stationary abutment of insulating material on that side of the inertia member remote from the actuating means, whereby sufliciently great hydrostatic pressure will cause the actuating means to force the inertia member against said abutment and thereupon will close the said contacts.

Hilbert et al. Nov. 15, 1938 Yarbrough et a1 Mar. 28, 1944 

